The museum, to open in two years' time, will occupy 6,000 square metres of the underground rail network in Milan where hundreds of Jews from Milan and nearby were gathered to be sent to Nazi death camps such as Auschwitz and Dachau.

Platform 21 was part of an underground railway network that mirrored overground passenger lines and was used to ship goods through Milan's Central Station, which was in those days the clearing house for half of Italy's rail freight.

But in World War Two it was put to more sinister use.

''The Jews were loaded onto the wagons in secret,'' said Michele Sarfatti, head of Milan's Contemporary Centre for Jewish Documentation. ''We historians have only recently rediscovered this piece of Italian history as no traces were left.'' More than 60 years after the war ended, Italy is the only major European country not to have a Holocaust memorial, though plans to build one in Rome are underway.

At least 850 Jews went through the belly of Milan's main station before being shipped off to Germany and Poland. Most of them never came back.

Sarfatti said little information had survived about how Jews were deported from Milan as everything happened underground at night and even the few survivors could not clearly tell where they had been taken.

The fascist regime of Benito Mussolini imitated Germany's Nazis to introduce anti-Jewish laws in 1938. But deportations started only after September 1943, coinciding with the German occupation of northern Italy.

Of the estimated 7,800 Jews deported from Italy, just over 10 percent survived. A total of six millions European Jews and millions of others, including Poles, Russians, homosexuals and Gypsies were deported and killed at Nazi concentration camps.